Power-transmission device.



0. H. NORTON.

POWER TRANSMISSION DEVIGE.

APPLICATION FILED AUG.15, 1913.

Patented Nov. 3, 1914.

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G. H. NORTON.

POWER TRANSMISSION DEVICE.

APPLICATION FILED AUG. 15, 1913.

Patented Nov. 3, 1914.

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UNITED STATES PATENT OFFICE. I. I

CHARLES H. NORTON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO NORTON GRIND ING COMPANY OF MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

POWER-TRANSMISSION DEVICE.

To all 10 7mm, it may concern Be it known that I, CHARLES H. NORTON, a citizen of the United States, residing at- Vorcestenin the county of Worcester and State of Massachusetts, have invented a new and useful Power-Transmission Device, of

which the following is a specification.

This invention relates to grinding machines,' and particularly to an improved driving means for the head-stock of such machines.

It is customary in grinding machines of usual construction to support the work upon non-rotatable or dead centers and to provide a driving plate mounted upon a work driving gear for rotating the work supported upon the centers. This gear meshes with and is driven by a pinion mounted on a pinion shaft bearing a cone pulley to which power is transmitted by a driven belt. a For well known practical reasons, the teeth of small pinions can rarely be formed to correct theoretical outline and the variations from such outline, together with other slight imperfections and irregularities in the teeth and the unavoidable back-lash between the parts, combine to produce variations in the relative circumferential speed of the pinion and the gear. Assuming the rotation of the pinion shaft and pinion to be constant, the corresponding rotation of the gear is more or less irregular and intermittent, producing imperfections in the work called chatter marks which, when magnified, appear as a series of straight lines or minute grooves parallel to the axis of the work.

The object of my invention is to provide a grinding machine in which irregular or intermittent rotation of the work driving means is avoided, whereby work ground on the machine will acquire a better finish than has heretofore been produced. With this object in view my invention contemplates the provision in a grinding machine of means insuring constant speed of rotation of the work driving member, and means permitting variations in the speed "of the driving pinion. I

My invention further consists in the devices, arrangements and combinations of parts hereinafter described and claimed, the advantages of which will be obvious to one skilled in the art.

Specification of Letters Patent.

Application filed August 15, 1913.

Patented Nov. 3, 1914. Serial No. 784,904.

having my improvements embodied therein;

Fig. 2 is a horizontal transverse sectional view taken through the head stock on the line 22 of Fig. 1; Fig. 3 is a sectional view of certain parts shown in Fig. 2, but on an enlarged scale; Fig. 4 is a sectional view of the spring container and cushioning springs, taken on the line 4-4 in Fig. 5; and Fig. 5 is a transverse section taken on the line 55 in Fig. 3.

My invention is herein shown as embodied in a grinding machine of usual construction (see Fig. 1) having the base 10 supporting the sliding table. 11 upon which is mounted the swivel table 12 supporting the head stock 13. The machine is also shown as provided with a grinding wheel 14 mounted within a guard frame 15 and driven by a belt indicated at 16. No part of my invention resides in the elements above indicated, which may be of any usual construction.

Mounted within the head stock 13 as shown in Fig. 2 is a non-rotatable sleeve 17 within which is secured the dead center 18.

driving gear 20 which may be retained upon the bushing by a plate 21 secured to the end of the sleeve 17 by screws 22.

A work driving plate 23 is mounted upon the gear 20 and may be secured thereto by screws 24. The driving plate is provided with slots 25 within which are secured the work driving pins 26. The outer portion of the work driving plate is materially enlarged and thickened as clearly shown in Fig. 2 and the driving plate thus performs the functions of a fly wheel in addition to driving the work.

A pinion 27 is mounted upon the pinion shaft 28 and meshes with the work driving gear 20. The pinion shaft 28 is rotatably mounted in bearings-29 and 30 supported in arms 31 and 32 projecting from the head stock 13.

Loosely mounted upon the pinion shaft 28 is a two-part cone pulley comprising a main portion 33 having an elongated sleeve 34 constituting a rear bearing for the pulley and having a ball bearing35 of any 'ordi nary construction for supportingthe front end of the main portion. The bearing 35 may be retained within the pulley by a cap 36 secured to the pulley by screws 37 (see h ig. 3).

The second part 38 of the sectional pulley fits loosely over the sleeve 34 of the main portion and may be rigidly secured thereto when desired by a screw 39 passing through both parts and provided with an internal aperture 40 through which oil may be introduced to the pinion shaft 28. A headless screw 41 is provided for closing the aperture 40.

The sleeve 34 of the main portion 33 is provided with a pair of diametrically pposed slots or openings 42 and the part 38 is provided with a pair of diametrically opposed recesses 43. Within each of the recesses 43 is mounted a spring container 44 (see Figs. 4 and having a pair of apertured projecting arms 45 within which is mounted a short shaft or rod 46, supporting a pair of compression springs 47 The pinion shaft 28 isprovided intermediate of its length with a transversely threaded opening within which are secured a pair of forked studs 48 projecting through the slots 42 and into the recesses 43 where their forked ends partially encircle the rods 46 and are received between washers 49 pressed inwardly by the springs 47.

In the process of assembling the mechanism described the main portion 33 of the cone pulley is first mounted upon the pinion shaft 28 after which the forked studs 48 are inserted in the screw threaded opening in the shaft and thespring retainers are then slipped radially over the ends of the studs. The section 38 of the cone pulley is next moved axially along the sleeve 34 until the spring retainers 44 are firmly seated in the recesses 43. The screw 39 is then inserted to secure the parts firmly together.

From this detailed description of my invention, it will be evident that I have provided a driving gear having a fly wheel attached thereto to steady its motion and a driving pinion mounted upon a pinion shaft to which power is transmitted from a cone pulley entirely through cushion driving connections. With this construction the work driving gear and the work driving pins carried by thework driving plate are given steady and constant rotation due to the inertia of the fly wheel while the variations in speed produced by the irregularities of the teeth are thrown back into the pinion and pinion shaft, the cushion driving connections permitting variations in the speed of the pinion shaft while the cone pulley is being rotated at constant.

speed by the driving belt.

By the combination of the fly wheel upon the driving gear and the cushion connection upon the pinion shaft, I secure a steadiness and regularity of rotation of the driven work which could not be secured by the use of either of these devices separately.

While a preferred form of my invention has been described herein, it is evident that many modifications of the same can be made by one skilled in the art within the spirit and scope of my invention, and I do not wish to be limited to the precise details disclosed, but

What I do claim is 1. In a grinding machine, in combination, a work driving member comprising a gear, a pinion meshing with said gear, a pinion driving shaft, meansfor securing uniformity of the rotation imparted to the work driving member, and means constructed to permit variable rotation of the pinion.

2. In a grinding machine, in combination, a rotary work driving member comprising a gear, a fly wheel secured thereto, a pinion meshing with said gear rigidly mounted on a pinion driving shaft, driving means for said pinion shaft, and cushion connections between said driving means and said shaft so constructed that variations in the speed due to irregularities of the gear and pinion teeth will be absorbed by said cushion connection, thus permitting constant lsapeed of rotation in the work driving mem- 3. In a grinding machine, in combination, a work driving member comprising a gear, a fly wheel secured thereto, a pinion driving said gear, driving means for said pinion, and spring connections between said driving means and said pinion constructed to absorb variations in speed due to irregularities in the gear and pinion teeth.

4. In a grinding machine, in combination, a work driving gear, a fly wheel secured thereto, a driving pinion, a shaft for said pinion, a cone pulley loosely mounted on said shaft, and a double acting spring cushion connecting said pulley to said shaft.

5. In a grinding machine, in combination, a work driving gear, a fly wheel secured thereto, a driving pinion, a shaft for said pinion, a cone pulley loosely mounted on said shaft, a pair of forked studs secured in said shaft near the center thereof and projecting into recesses in said pulley, and a pair of compression springs in each recess yieldingly connecting each stud to the cone pulley.

6. In a grinding machine, in combination, a work driving gear, a fly wheel secured thereto, a driving pinion, a shaft for said pinion, a cone pulley loosely mounted on .said shaft, and cushion means connecting said pulley and said shaft, said pulley comprising two sections rigidly secured tofor gether, and said cushion means being mounted in recesses between said sectlons. 7. In a grinding machlne, 1n comblnatlon,

a work driving gear, a fly wheel secured thereto, a driving pinion, a shaft on said pinion, a two-part core pulley loosely mounted thereon, and cushion driving connections between said shaft and said pulley, the main part of said pulley having a projecting sleeve rotatable on said shaft with a pair of diametrically opposed transverse slots therein, the second part of said pulley being rigidly having a pair of diametrically opposed recesses in the large end thereof, and said mounted on said sleeve and p cushion driving connections comprising a pair of forked studs fast in said shaft and projecting through said slots into said recesses, a spring container secured in each of said recesses, and a pair of springs mounted in each container to hold one of the forked studs yieldingly in spaced rela-' tion to said container. 1

In testimony whereof I have hereunto set my hand, in the presence of two subscribing witnesses.

CHARLES H. NORTON. Witnesses:

ALBERT TURNER, HOWARD W. DUNBAR. 

